Method and apparatus for reducing capacitively coupled radio frequency energy between a semiconductor device and an adjacent metal structure
US7204701B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 8, 2004 |
| Grant date | Apr 17, 2007 |
| Priority date | — |
| Expiry date | Mar 8, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2201/2009
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A bolster plate apparatus, used to secure a semiconductor device intermediate a printed circuit board and a heat sink apparatus, includes either an indentation or an open aperture into which a radio frequency absorptive material may be disposed. The absorptive material may be a ferrite material specifically selected to absorb frequencies in the range of the second to fourth harmonic of the processor clock signal frequency. The type of the ferrite material implanted in the bolster plate is selected to maximize the absorption of radio frequency energy, particularly that emitted at the pad vias on the underside of the printed circuit board, without affecting the signal integrity of the other pad connections. The shape of the cutout or aperture is also defined by the arrangement of RF emitting pads on the underside of the printed circuit board. The open aperture, without any absorptive material, effectively increases the distance between the source of the radio frequency energy and the metal body of the bolster plate, thereby reducing the amount of radio frequency energy absorbed by the bolster plate and the electromagnetic interference generated thereby. Also disclosed is a method for…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.